Powerline networks operate by transmitting signals between network devices along the powerlines within a premises, such as a house, an office, an apartment etc. Powerline networks are considered desirable over other wired technologies, like coax or phoneline networks, because power exists in every room of a premises; there is no need to add additional wiring to reach the current location of the connected device.
Unfortunately, as shown in FIG. 1 to which reference is now made, powerlines in multi-dwelling buildings, such as office buildings, hotels, apartment buildings, etc., extend from one premises 10A to another premises 10B. While premises 10A may have its own network 16A and premises 10B may have its own network 16B, and while both premises 10 may have a switching board 11 (shown attached to a separating wall 12) which may connect the powerlines of a premises together, switching boards 11 also electrically connect the in-premises powerlines to the same main powerline 14.
Thus, a signal 18 sent from a PLC (powerline communications) node 20B, forming part of network 16B, to another PLC node somewhere in network 16B may travel along powerline 14 into network 16A of premises 10A (nodes 20 are shown as computers with the PLC units embedded therewithin). PLC node 20A, of network 16A, may receive a version of signal 18, as signal 18′, even though signal 18′ was not sent by any of the network devices in network 16A. In some cases, signal 18′ may be attenuated to a level lower than signals 22 sent by network devices in network 16A. In other cases, signal 18′ may not be much attenuated such that it can be received at levels exceeding those of signals sent by the devices within the network. In FIG. 1, signal 18′ is shown with dotted lines while signals 18 and 22, sent within their respective networks, are shown with solid lines.
U.S. patent application Ser. No. 10/950,262, filed Sep 24, 2004, now U.S. Pat. No. 7,830,907, handles signals like signal 18′ by coordinating the usage of network resources between the neighbouring networks. This approach is suitable for the case where the cross-talk signal level is high such that overlapping with the cross-talker must be avoided.